feat(ui): Add quality selection for audio-only content

[nbcl]

The present pull request aims to provide a solution to #2071 (Quality selection UI for audio-only content) by replacing the resolution selection menu with a quality selection menu in audio-only content.

Fixes: #2071

How to preview

Initialize the client with a config that contains quality in the controlPanelElements and load the player with an audio-only manifest.

const config = {
 'controlPanelElements': ['quality'],
}
ui.configure(config);

await player.load('https://storage.googleapis.com/shaka-demo-assets/dig-the-uke-clear/dash.mpd');

Changelog

test/ui/ui_integration.js

Removes the integration test that checks for a hidden resolution button in audio-only content.

test/ui/ui_unit.js

Expects the correct version of the resolution button and appropriate bandwidth parsing for an audio-only manifest.

ui/locales/en.json

Adds the quality locale as reference in English.

ui/locales/source.json

Adds a description and meaning for the quality locale.

ui/resolution_selection.js

Removes TODO fix that hid resolution button for audio-only content by adding the removal of duplicates, sorting and naming of available tracks flows for either video or audio-only content.